1. Field of the Invention
The present disclosure relates generally to hybrid type magnet bearing system, and more particularly to bearing system uses permanent magnets to replace mechanical bearings and to provide axial and radical bearing functions simultaneously.
2. Background of the Related Art
The relative motion between different structures of a mechanism is very popular for industry and daily life. The bearing is popularly used to stable and support the action of the rotation axis when one or more of movement and/or rotation are required. For example, the ball bearing, the roller bearing and the needle bearing. Essentially, the bearing provides a rotation support between the rotator and the stator, so that the rotor indirectly contacts with the stator. Hence, the rotation and the movement of the bearing may reduce some disadvantages induced by the relative motion between the rotator and the stator, such as friction, vibration, noise, lose, and so on. However, the loss of the bearing itself also is un-avoidable. Hence, full lubrication and periodic maintenance are required, and then higher cost and lower throughput are unavoidable disadvantages.
In general, the loss of the bearing is a function of both the rotation and the movement between the bearing and the rotor/stator, i.e., the combination of the rotor and the stator. The higher the rotation rate of the bearing, the larger the dynamical frication loss between the bearing and the rotor/stator. Besides, due to the direct contact between the bearing and the rotor/stator, the static friction coefficient therebetween also is a key factor about how the motion of the bearing is driven by the rotor/stator. The loss of the bearing also is related to the details of the relative motion between the rotor and the stator, where the rotor and the stator are positioned over two opposite sides of the bearings. When the two structures (rotor and/or stator) over opposite sides of the bearing are only rotated around one same axis, the bearing only has to satisfy the requirement of axial motion. In contrast, when the two structures (rotor and/or stator) over opposite sides of the bearing are rotated around the same axis and moved perpendicularly to (radically to) the axis simultaneously, the bearing has to satisfy the requirements of both the axial motion and the radical motion.
Particularly, in a perpendicular mechanism, two structures (rotor and/or stator) on opposite sides of the bearing are perpendicularly arranged. Hence, the weight of the upper structure, even the weight of other elements positioned on and/or over the upper structure, is supported by the lower structure. Clearly, the bearing loss or other disadvantages will be more serious along the perpendicular direction. Accordingly, the axial bearing has to be particularly designed and will increase the complexity, cost and maintained difficulty of the combination of both axial and radical bearing system.
Accordingly, it is desired to develop a new bearing system for improving these disadvantages of the bearing system used to provide rotation support between two separated structures.